Unequal Load Balancing + GLBP

Hello and Good Day.

I have a somewhat unique configuration that connects 2 networks, as
described in the following (ascii) figure:

Network A
--------------------------------------------------
| | | |
---------- ---------- ---------- ----------
| Rtr A1 | | Rtr A2 | | Rtr A3 | | Rtr A4 |
---------- ---------- ---------- ----------
: + \ : + \ : +
: + \ : + \ : +
: + \ : + \ : +
: + \ : + \ : +
--------------------------------------------------
| Rtr B |
--------------------------------------------------
|
--------------------------------------------------
Network B

whereas the ':','+','\' indicates links with different characteristics
(i.e., bandwidth, latency, bit error rate, etc.).

There are various hosts at each network representing different
systems: VoIP, Live Video, Video Conferencing, WWW, etc. Each system
has its preferred links (!) between the networks.

My goal is to configure the routers properly so that I can fully
utilize all the available bandwidth between Net A to Net B and between
Net B to Net A - on all the available links (!).

Part of the solution is to implement GLBP at Net A routers. However
this doesn't solve the problem of unequal load balancing between the
routers of the 2 networks.

I'll appreciate any suggestions/guidelines for a possible solution.

Happy New Year.
Lior.

Lior Shadhan