fixed the link typo sorry

that digital servo is too big for micro heli.

tail servo - hitec HS56 or hs50 // there's also a micro digital servo for $25 that www.allerc.com offers, which i heard is pretty good.

the lipos you currently have are perfect for either Trex or X400. What is the C rating on them? a logo or ec8 will require like a 5 or 6 cell lipo and that's $$$.