I'm not knowledgeable enough yet to tell you the differences between the T-3 and the EVOD, other than the obviously different tanks. Both are bottom coil clearos, and both have gotten good and bad things said about them on the forums. They both use the same replacement heads as far as i can tell. Some just don't like clearos at all, and some love them, both for very valid reasons. I got a couple to see if I would like them, and I do like them, however I can see the not so great it them too. That's why I would recommend trying a 5 pack of +/- 2 ohm single coil cartomizers along with whatever clearo you want to try. You will be able to learn how they work and get a feel for the vapor and taste differences between the 2, and they are relatively cheap.
More importantly, at least to me, is that you get a good battery(s) and I think the ego VV or vision Spinner VV in at least 900 mAh is a better starting point than where I started. Like I said earlier, I'm eyeing the 1300 mAh vision Spinner right now, but will be waiting awhile to upgrade because I've spent enough money on what I have now and it's keeping me off the smokes just fine. Which is my ultimate goal, and not having a wicked vaping rig. Although some of them are really nice looking.
My first juice order was from Madvapes. I thought I wanted to replace smoking cigs with vaping tobacco flavored juice so I ordered 10 ml of their tobacco, and thought since I was paying shipping I would try a couple of 5 ml flavors that caught my eye. One is Spearmint and the other is Sweet Carolina. I ended up liking the sweeter vape from Sweet Carolina that either of the others and keep a carto filled with it all the time now. I realized quickly that tobacco flavor wasn't going to replicate cig smoke like I thought it would. I do use the tobacco to mix with other juices to give it a more earthy flavor so it won't go to waste.
I then made an order with Mom and Pop's for a few of their juices, listed below with a quick thought on each-
Pchela's Famous 5 Layer- Really sweet in a pleasant way. I mix it 50/50 with tobacco most of the time. I enjoy it.
Scuba's Orange- I love this one, nice smooth orange flavor, not over powering.
RYO Tobacco- I was warned, didn't listen, still trying it every once in awhile, will probably be using to mix with sweet juices.
American Blend Menthol- Not bad every once in awhile, I'm not huge on menthol.
Vanilla Cream- Just OK for me. Not great, not bad. Seems way better with a fresh battery so I suspect a higher voltage would help this.
RY4v2- So far my favorite, spicy tones of tobacco, a nice caramel, and a hint of vanilla.
For juice, I'd start with 4-5 small bottles from a vendor that catches your eye, or get a sample pack if that interests you. Order at the same time as when you order the gear you decide on so it all shows up at roughly the same time, and start experimenting with what you have. I really think that once it's in your hands you won't have a problem getting it all rolling, no matter what you choose. Keep it simple to start, and enjoy the process.
I hope some of that helps.
