99 regal GS engine troubles

I desided to rip my GS engine apart because a few months ago I lost power and the engine started rapping.
It came back to life for but didn't run well.
#1 cylinder has low compression and engine runs ruff skipping ETC.....
things has aboult 155,000 miles on it.
It had been skipping for awhile even before the engine noise.
I replaced the plugs and wires but it still skipped alot when idling.

I guess I really finished her off.

I was just wondering if ther are any things I should look for or when rebuildng this thing, if anybody has some ideas to make my life easier would be great.
I wouldn't mind hyping this thing up a little while it's apart or should I stick with stock items.

What's the best gaskets to use on the heads and intake?
Should I have these heads sent out for inspect?

Also the exhaust broke at the flex pipe where it bolts to the manifold.
Probably from the engine running so ruff it gave out.

You think I should go with theaders now or something bigger.

Just wanted some input if possible.

Thanks