Honestly, I love IP (Network) control so much that in your position I would make a small network just for the remote. Plug in a router ... instant network. Some models will mirror your upstairs network and bring Internet downstairs for you. I hate "streaming" but there is a lot of great stuff online and I would seriously make an effort to bring the capability to any new HT.
But,... I don't want to be pushy... you want what you want naturally. Like you my gear sits outside the "HT" (or at least that's what I gather from you image you posted). I used an IR Repeater ... in fact you can have it if you want it but it's Radio Shack and it's likely just as cheap to buy a new one than to ship this one...Anyways,.. can't stand the flaky-ness of it at all...Also the remote doesn't know what the status of the gear is sometimes. I can't have that anymore ... I wouldn't be able to deal with my kids coming to me not knowing how to use the system.
So,... I actually don't know all that much about RF to IR except what I've seen over at Roomie Remote's ... web site. That's the remote I use and love. I used to use Harmony though and I believe there are models that transmit RF (and IR) and that have a little box that receives the RF and transmits IR ... (that could eliminate the need for the repeater if you're lucky.)
Hopefully, others will chime in ... Because ,.. I'll just keep nagging you to go with Network control... ha ha.