While we all dream of big fast, long focus draw cinema lenses (Panny primes, etc.), you can get away with using still lenses if you use the right ones and mate it with a decent follow focus and some focus whips (for example, from Redrock Micro, but there are many other options). I'm currently using old Nikon AI-s primes from the 80s. They have the advantages of rugged build and long (pre-autofocus, 270 degrees+) focus pulls. Now, you still don't get the super accurate distance marks, and that where I find the follow focus gets to be invaluable. If you work with actors who can hit marks, you can mark off your points of focus as needed and get very clean rack focuses. It's not ideal, but you can BUY many of these lenses for under 300$ (and some under 100$) and get great quality from them. I'm not an expert, but this has worked for me on a budget, and it might be worth trying with a rental from borrowlenses.com.
In terms of sharpness, I would be surprised if the L lens was the issue with the house episode. These lenses resolve cleanly for 25 megapixel stills, I don't see how they would fail to resolve to a binned 1080p image. I would expect any issue with sharpness was either due to intentional softening (to avoid moire and aliasing) or due to the codec the 5D spits out (it's not bad, but it's not great either). That's just my .02, if I'm wrong, I'm wrong :-)
Hope I was helpful.