need pre amp suggestion

If I were you I would stick with a McIntosh pre to go with the amp. Best match. The 28 seems pretty ancient but you should be able to find a more up to date model used.

As an aside, if those Gallo's are coming in new make sure you follow the manufacturer's break-in guidelines religiously. If you do you will be very happy with them.

Gsxr750ccs - Many factory preamps have too much gain. Its best to be able to set your volume control at half-turn for the volume you normally listen. Mid-way is generally the most linear position. Also, yuo'll have more volume selection when the gain is not so high, allowing for more gradations. You don't need to know what to ask for. Discuss with Dr. Peppard and he will offer an optimal solution. Don't be askeered. He offers a trial period. He's great and very patient and helpful. Give him a call or e-mail.

There is a VTL 2.5 listed for less than $1000,it is a very musical unit. VTL has a wonderful sound.
Good luck in your search
Jeff

Mapletree is overachiver at its asking price.
But it all depends on the sound characteristics that you are looking for. In my opinion, Gallos could use a little warming up with tube preamp. At least that is how I feel YMMV.
It holds its value and it's very popular......if you decide to sell it in the future.

Cheers
Mariusz