I second Al Ray's suggestion of a Nelspot. Since you already own a nelson style marker, it makes good sense. the Nelspot and phantom share a lot of the same internal parts, such as springs and seals. Cuts down on part hunting.
Not to say you shouldn't try a PGP. I have a buddy who loves them.
Of course the wonderful thing about MCB is that if you purchase a marker and find you don't like it, one of the other whores here will most likely take it off your hands. Then you can purchase something else.
It takes more energy to frown than it does to smile!
You know, it takes more energy to point that out than to leave me alone.