No, they are both different, Megamod has been in progress for years and is nowhere near completion yet. Killap has been squashing bugs in the original program for just as long, at least, and that has been his focus. Restoring has been the task he took up. Making it "work the way it's supposed to" led to him including some unused material that eventually became the Restoration Project, if I was to guess.
Restoration Project can't really be compared to Megamod. Both mods are by two different modders with different ways of doing things. RP is meant to be a perfected version of the original game. You can actually go places and do things as originally intended, which makes a big difference. Any bugs you get playing RP are tiny glitches killap hasn't found and made perfect yet. If you want Fallout2 the way it was meant to be, then RP is the only way to go.
Megamod is a personal effort to put all available mods into one. If you want something different then Megamod is the way to go.
Whatever you do, I suggest to copy an original Fallout2 folder entirely and put it somewhere else under a different name - twice, if you want to play both.
Killap's mod will change the icon of the .exe, but nothing to worry about unless you hate his bear-like face.
Edit - Sorry, not disagreeing with Brother None any. RP is the way to go for noobs.