Given your requirements - the player needs to be quick heavily customised.
I'm not entirely sure if this player can do it.
I know a lot of the MP4 players can't be this heavily customised - mainly due to the fact that development kits are not released for these type of players. The manufacturers are heavily into protecting their IP so don't release development kits.
What is your budget? Have you thought about
OPEN SOURCE portal media players instead?
Take a look at this site:
GBAX.com and here:
GP32X.COM. - it covers a lot of open source portal media players. I think this is your best option as it would be a lot more hackable than the Visual Land players I would say.
I had a
GP2X quite some time ago and it's great! Lots of things you can do with it, it's Linux and open source with a software development kit available too. The official website is here:
FUNGP if you want to ask them more about it. But if you read more on the forums and community sites, you should hopefully find an answer there.
Hope that helps.
Let us know how you get on as I would be interested......