Get a cheap Garmin eTrek for around £100, then go to aeroplanner.com and download 'data chunks'. These data chunks contain waypoints of VORs / NDBs / Airports / VRPs / intersections etc etc. Once these are on your GPS you do not need a 'proper' moving map, and in fact they're probably more accurate than most moving maps you get on handheld GPS's. It also saves you getting a Pooleys GPS companion and typing all the WPs in.
I did a comparison between the handheld eTrek with waypoints from Aeroplanner and a (cantrememberthenameof) panel mounted IFR certified GPS last time I was in the US. It was spot on.
The eTrek is 12 channel same as most GPS's on the market so accuracy will be or should be exactly the same as a more expensive model. If you're feeling particulaly flashy, spend another £100 and get the eTrek with barometric altimeter built in...
Cheers
EA