Hi Dallas Ed.
Nice to hear you. Im in the UK.
Firstly, before you go any further, simply try buying a KR808D-1 Battery. It can be used with your 901. Its not just going to change your impressions of the 901, but its a convenient battery to have lying aroung. Can be used with the 901 easy.
You may want to get a KR808 starter kit so you can try the cartomizer method too. That way youll have 2 KR batteries.
In fact, whatever you do decide on purchasing whatver it is (even if you purchase a diamond set mega mod ecig or GG or Super T or whatver), you might as well (and should) include 2 KR batteries (£7 each) in your order just so you can know what you have been missing all this time ( I cant believe youve only done the 901 on its own battery). I dont think youll regret it.
Try it and tell me the difference - its makes a huge difference using your 901.
Secondaly, if you want to experiment buy a:
801 Battery
and if you want, a 501 Battery for example an eGo battery or a Riva battery.
Then buy a 801 to 901 adaptor (£3) and a 510 to 901 adaptor (£3).
Then use your 901 with the KR8081-D battery, and then with the 801 battery using the adapor and then the 501 battery using the adaptor, and then with just the Riva (doesnt need an adaptor as it is already made for a 901 and has a 901 thread).
so youll have
1) 901+KR battery
2) 901+801 battery (need screw on adaptor)
3) 901+501/ego battery (need screw on adaptor)
4) 901+Riva
Ive tried 1, 2 and 3.
For months 901+KT Battry (no.1) was unbeatable - it still is. It blows away the 901+901 battery and then some. There is no comparison.
BUt then, after vaping on my B112 Attomizer+801 Battery (they are made for each other even if they arnt sold together), and liking the really easy natural draw, i got an adaptor for my 901, and yes, the 901 vapes a little more naturally and effortlessly on a 801 battery then a KR Battery (which itself vapes much more naturally then a 901 battery) but the TH is a little bit diminished, which lead me to believe best 901 is a 901+KR battery.
Ive just begun ... i could go on ... but I wont becuase these can be headaches to read, but to summerise just on a 901 Attomizer level:
901+adaptor+801 battery is similar to 901+KR Battery, but both combinations >>>FAR EXCEED in every department and experience >>>> the 901+901 Battery.
So, imo (and in the opinion of many others on this board i would think) whatver you end up buying as a kit for your wife, throw in the KR8 auto batteries (they come with buttons, but i prefer auto) - they are very handy to have around (last very long and match very well with the 901 and give it more kick).
Id definately buy the KR801 battery (£7) if i was you just to understand and be able to compare subsequent attomizer and battery discussions.
To answer your question though, My "best" ecig so far is the BE112+801 Battery but thats with my best ejuice too - Johnsons Creek. Its a different league and entirely different ecig then if i use other 'normal' eliquids on it (which i have done and dont get the same satisfaction).
So, id say eliquid is As if not MORE important on satisfaction of ecig use, and I would say there is no better all round juice then Johnson Creek or its Red Oak range. Again , it makes all my ecigs completely different and more natural/powerful ecigs.
Word of note: On my BE i use soft-spongy tip cartridges. I dont know if these are 801 or RN Penstyle carts or even BE Carts (I threw away the boxes, manuals and packaging so I cant remember). I do know that one set of cartridges I bought had hard plastic ends - like the 901, 501 or any other ecig - but one set had a bitable, chewey tip, which adds to the natural and very comfortable feeling of vaping on my BE112. You can vape on it better in my opinion and "bite" the end as you could a real cig/cigar.
i think the tip is an 801 whistletip.
Having said that about my "favourite" ecig, I alternate using it with the 901+KR battery using Cigar elquid which gives me a great vape. tonnes of vapour and a good + strong TH.
I have no mod yet. I may get a Little Sister Variable Voltage box mod (cheapest variable voltage i think) to try vaping on a higher voltage and find my sweet spot. But ease of draw is important for me, so i want to wait to get a variable voltage variable draw machine instead!
Having said all that though - I still prefer smoking! ha ha!
Would you recomend me the 601 pipe? Would that help me stop smoking completely!?!?!?!
It can get every possible battery, every possible atomizer / cartomizer and it cannot stop working while I am away from home (fully mechanical and indestructible). It's switch position looks awkward at first until you try it, then you see that is extremely comfortable. It also has great safety features (spring fuse, vent holes). If I was limited to one mod only, this would be my choice. 
