At the moment mine get a mix of Allen & Page Fast Fibre, Dengie Good Doer & Top Spec Lite (LU) or AntiLam (Jim). The FF is really only added to mix Jim's supplements in, he tends to leave them if the feed is dry & the Good Doer doesn't damp down very well.
I think TS Lite is meant to be the lowest calorie balancer on the market & Good Doer seems to be the lowest chaff I've found that's easily available.