Last year when I grew sweet potatoes I just planted a single whole potato in my buried wood bed, and it produced about ten pounds of tubers, so I think it was a decent return on my investment. In the past I had planted slips, but they didn't produce nearly as well as the whole tuber. The problem with the "whole tuber" method is I'm limited to the variety offered by the grocery store.
If your soil isn't horrible, I'd just sheetmulch the clover with cardboard and lay mulch on top of that. Go easy on the compost.....sweet potatoes don't like an excess of nitrogen. Let the area settle for a while and then punch holes through and plant slips or tubers and watch it grow. Unless you're in the mountains you can probably plant up through June and still make a crop. And another hint.....eat the greens! A lot of folks don't know that. They make an excellent substitute for spinach lightly cooked. If space is limited pruning the vine tips for greens achieves two purposes, and you can take up to 20% of the foliage on a big sweet potato plant without damaging the root yield. But beware of deer. They know those greens are good to eat too!