Down by the river would be perfect. I also think driving into Terre Haute and being able to see the stadium and its light would be awesome, especially during a night game. Since I take 63 into the Haute, I'd put the field on the south side of the Wabash where it runs east-west after going under the highway. Clear just enough trees so the stadium is visible from the highway. (I'll use 'Memorial Stadium' as the name for now) Would a "Memorial Stadium - Exit ahead" sign be cool or what? I'd build an exit right off of the highway, only way to get to the stadium. Make around a mile and a half drive directly towards the stadium; signs, statues, and Sycamore trees on both sides of the drive. The largest part of the grandstands facing the drive with huge posters of current players (and Miles) on display, visible from the exit.
Parking lots on the east and south side of the stadium. Enter the gate right after the transplanted Sycamores(mentioned in other posts), walk through the football hall of fame to get into the stadium which holds 20,000. The east grandstands will be double decked with a press box atop, painted blue. The south side is a semi-circle where the band and student section will be. Will that student section be filled is another question. The locker room is located between these sections, with a tunnel entrance. West side is only one level, stretching the length of the field, and at the end will be a three story "tower". Top used for cameras, bottom two levels are restaurants with viewing access of the field, and the third floor is the "VIP" box, with a perfect view of the field and the river to the north and west of the tower.
No seats to the north, left open for a view of the river, and passerbys on the highway. I'm trying to think of something for Sam down there, something like what Bernie Brewer does, the treehouse might just work. An inclosed practice facility with a weight room, offices, film room, everything needed, on the opposite side of the south parking lot from the stadium.
I asked the philanthropist and he said use the money for whatever once the greatest football stadium ever has been built. I'd also use some money to rival Oregon's uniform selection of 384 combinations, just not too much black. The one combination of all charcoal black, though, will be worn on the annual night game televised by ESPN.