Stako's are a 5 year only bottle, they are light weight and once they have reached their 5 year life are considered disposable despite their price!
Good compact 'peanut' bottle choices in 68/45 size are DXS/Smartparts/Dye/CP, these are Inocom bottles
Think Ninja are finally producing a Pi marked bottle but don't know if this is a c ompact bottle.
You best bet so far are the Safer/Fuel range, nice short stubby type 68's.
http://www.bzpaintball.co.uk/product.php?p=Fuel Supralite Air System with Ninja UL Reg&t=Air Systems
Here's a pic of a few bottle, pity I never lined them up properly to compare the length.
L-R, Standard 45/45 PE bottle, PE bottle G2, DXS with Ninja, Standard PE 68/45