Maybe the simple heat pipe recipe, limited to 100 - 200 MW /s, (120-150 would make more sense for 10-12 exchangers). Then the normal heat pipes are more expensive (normal cost) and take tier 1. Normal heat pipes can transfer 1GW. There's also room for a 3rd tier: Higher temperature and/or greater throughput, though that also requires a reactor which can reach a higher temperature to achieve longer runs of heat pipes. (or tier-2 pipes that have more base_area or have longer undergrounds, so they can transfer more per tick, simplifying water and steam transfer)

I might do that at some point in the future, but I won't do it in this mod. The reasoning behind that is that this mod is supposed to change the cost of heat pipes, not add more / change them.