I don't use a rig quite like that, so I can't advise, but...
Get an old rope, knot up a section (rather than eye-splice) and experiment. You should have a pretty good idea within 10 minutes of what will work and what won't.
I use a VT on Beeline for a self tending friction hitch, I set mine at 28". I am currently experimenting with both spliced and knotted versions. E2E without a hitch climber will punish the climber with the extra slack, so you may prefer longer if you have your rig set up to "raise the knot" as you ascend. Otherwise, shorter is better.
Beeline is pricey, but tough as all getout. Some have reported poor results, but I like it. VERY firm when new, it loosens up a bit with use. Icetail is simple to splice, many use it to make their own. I have heard that it gets a bit loose with use; it is also very strong and heat resistant. If you are going to buy a pre-spliced E2E, then buy one that is made of a tough material.