Who does dedicated occasional IP in North America?

I'm looking for a provider from whom I'll be able to lease blocks of "occasional time", as television SNG operators do now, but I need not only the timeslot on a transponder/carrier somewhere, but also an IP teleport at the other end, which I can use to VPN back to my main network.  I would assume I'll have to get both from the same provider, subleasing a slice of a transponder at which they've got a hub pointed.

My mobile setup is a 1.2m Ku dish on a Frontline DSNG truck, and I don't especially care what I put behind the L-band connector; an iDirect modem or a DVB-RCS would be fine, as long as it talks to the folks at the other end.

My target bandwidth is 2MB/s up, 1MB/s or so down; my primary application is streamed MPEG2 or MPEG4 4:3 SDTV video heading for my studio, where we'll re-uplink it to our dedicated C-band transponder as DVB-S.  My BUC is a 50-watt Upcom, so uplink power budget shouldn't be a problem.

My projected usage is 4-6 hour blocks, probably 1-4 times a month to start; any service plan that includes the words "per month" is not something I'm interested in.  I've found Mobilsat, who resell a service similar to this, and a bunch of iDirect providers, but none of those will do 1:1; 8:1 seems to be the highest contention rate I can get.  I want the carrier dedicated for the time period I've reserved.

I wasn't sure whether to ask who provides this sort of service in this board, the Mobile board, or the Bookings board; if someone needs to move it to a more appropriate place, that's fine.  (ETA: It would appear perhaps Bookings would have been better.  Perhaps if I didn't piss the moderator off too badly, he might move it there.  :-)