Engine Oil Leak

Hi Group, I'm new and really appreciate groups like this as they have been very beneficial for other vehicles of mine. Today's problem: My daughter owns a 96 4cyl(2.4?) with a 4spd?. This past summer she had to have a head job due to an overheating, from a leaking radiator. That was repaired by a reputable garage and she has since logged about 10k on. Now, the engine is leaking oil at a good rate, to the tune of 2 qts every couple days. I've had a couple garages eyeball it and one pinpointed oil/wetness on the injector side of the head, near the valve cover gasket.

Question: where is a most viable place for the oil to be coming from? The garage that did the head job says they have to remove some things to look at it and appears that they will charge just to do this. I'm suspecting that it's due to an inadequate repair job of the head, like valve cover gasket.

Years ago I took my German made car to Goodyear and they had a dye that they added to the crankcase which after a few miles driven showed where the leaks were.

Please give me some better options. Should we have the original garage finsh the job? Should we have a dealer look at it? Is it something I can do?

Thanks in advance for any advice.