To all of you that claimed otherwise, this can be done.
In fact quite easily (once one knows how)

Using Xincom XC-DPG502 Twin WAN Router (in UK it is less than 200)

It does load balance "out" connections & even with a little trick (using
Multiple DMZ) allows "in" access as if there was nothing there & you were
connecting straight to BM public interface (means BM does all the NAT etc)

Also connections "out" are having BM public IP as source (what I really

Anybody needs help please feel free to contact me

Other nearest solution was either Firebrick for over 500 or Xrio Q-Balancer
1510 for over 1200

Probably NETWalker Agile 200 High Performance Load Balancer

would do the same job

OK the cost (apart from money) is 3 public IP (load balancer LAN + WAN and
ADSL router LAN) on one connection & 2 public IP (load balancer WAN and ADSL
router LAN) just to connect

But after that is freedom....