It is not necessary to go as extreme as dayton on the batts and charger, though it would be nice.

You can find tenergy 6 cell 4500mah battery packs for $25 a piece brand new, not sure on what chargers are going for new, but I bought mine for $30 on ebay. You can also find clean used SV27's on ebay from $150-200 used and new/used.

As far as the SV goes, awesome boat, absolutely love it, haven't driven a fastech, don't really have to other than pure curiosity due to the fact I'm completely satisfied with my 2 SV's.