Neither of those are turbo's are ideal for OP. AVO380 is priced out (more money than a BnR20g) and the HTA68 is well known to produce less stellar numbers on pump than on e85. 20g is a tremendous DD turbo and OP already said... NO E85 and lower priced.
You can use a SMFW. The exedy/f1 is a single mass flywheel.