[sireat]

How do you set up load balancing for those two connections?

That is yourdomain.com -> IP_ISP1, IP_ISP2

Going the other way from yourserver -> outside would indicate some sort of bonding setup.

It is not trivial for a home lab.

I use 3 ISPs at home and just keep each network separate (different hardware on each) even though in theory the redundancy would be nice.

[johnklos]

Just use two A records for the one DNS name, and let the clients choose.

The other way is to have two names, like dl1 and dl2, and have your download web page offer alternating links, depending on how the downloads are handled.

You very rarely can do multi-ISP bonding, often not even with multiple lines from the same ISP, unfortunately.