WiFi Network Bridging

[Subeejit]

Hi all!
Need some help on WiFi networking.
I have 2 wireless routers connected to different ISPs for internet bandwidth. Since I donot have a load balancing router, I propose to allocate internet resource few systems from router#1 and rest from router#2. But in doing so it creates two different workgroups by which the basic LAN/ Printers etc. sharing between all the systems are effected.

I need a solution wherein I can allocate internet resource to specific PCs from specific routers but at the same time can have a single workgroup sharing the entire LAN resources as well.

Is there some way I can achieve this?

P.S. Both the WiFi routers are of Netgear make model#WGR614
All PCs are connected wirelessly and I donot want to invest in additional hardware.

Thanks in advance.