homeplug query

Hi all, firstly arent homeplugs great.

secondly the query.

does anyone know if it is possible to set up 2 networks using different speed homeplugs and same router?

basically i have 3 x 85mbps homeplugs that i want to use to connect my kids 2 computers (windows XP & windows Vista) to the router

then using 4 x 200mbps connect my computer and sky, 'an other machine' and the router.

effectively a fast network for me/sky etc and a slower 'kids' network.

I understand that due to compatibility issues i can't mix the 85 and 200 but can i run my 2 networks?

all help greatfully received.

ta