Considering the OP and jazdale's idea is just to drip to try flavors, then, maybe the BEST way to go IMHO is to be:
a fully de-wicked and de-bridged atty. Because it is EXCELENT to change flavors... It will never cause any flooding or clogging or whatsoever if you are gentle to it and ONLY drip one drop at the time (Once it is fully-primed). This drop will last around 4 good puffs and CHANGING flavors will be natural and .... It is PERFECT for that!
A 510 is in general a stronger 'hitter' but a 901 delivers more flavor. The 801 or similar are even better for flavors. But the thing to consider is that LR vs. Regular Res. will give different shades to the flavors, so if you aim at trying flavors when DIYing the best thing is to have an atty which will match the profile of the atty or set up which will be later used. If you are testing your liquids flavor-wise and you are to use them with an eGo T regular resistance atty, maybe the best thing is to drip into the very T atty. LR atties will make some juices better or worse, this being subjective of course; but there will definitely be a change you should take into account...
Just my two cents...