Playing HU poker with a small bankroll

[vlerk]

Some background: I've played 25nl and 50nl 6max on Party and FTP during the past year and have always been reasonably profitable in those games. I never played enough to build a decent bankroll for 100nl, became bored with 6max and cashed out. I have never seriously played SNGs. Recently I deposited $400 on Stars to start playing HU.

I'm now looking for some advice on how to proceed with this. Ignoring all BR guidelines I've been playing some (50nl) HU cash and noticed the rake is over 4ptBB/100. I'm far from sure I can beat the rake at this level, let alone actually build my roll. My BR is still around $400. Should I just suck it up for a while and play 25nl 6max until I have around $1000? Or would it be better to play HU SNG's for now? Which of these two options would better prepare me for HU cash?