1995 ej22 reseal and delta cams

Hi there everyone. For those who don't know, a few weeks ago I swapped a 1995 ej22 (about 200k miles) out of a Legacy into my 1993 impreza L. Put in a 2.5rs clutch at the same time. I have developed a leak from my valve cover gaskets. I needed a car asap and lacked money to do a correct reseal. Also, the "plate of doom" was plastic on it, cracked at that, and I could not find a metal one locally and I needed the car on the road. So I put some gasket maker over the cracks. It has held up, or so I think so far. But I don't feel like having to change it in winter with 3 feet of snow, outside. So that should probably be done to.

My questions:

• Is there a particular method for resealing these engines that needs to be adhered to?
• Should I buy anything specific?
• Anything else I should replace while I am in there?
• Should I replace the headgaskets (can it be done without a trip to the machine shop?)?

• I have been reading about Delta cams and how they make life awesome. This car is my daily driver, so I do like good gas mileage, but power is also important too. I have heard that 220's (It uses this kind right?) are the best option. I am new to this mechanical world though so can anyone tell me exactly what cams are going to do? HP gains, Mpg gains/losses, anything else they do?

I appreciate the help!