My suggestion is to buy the D&K replacement seals, which fit perfectly and will last for decades. Their foam product is designed to withstand the heat and extreme pressure inflicted by a vacuum press. And if you can get them $200, that would be a very good deal. Here are the current prices:
DK-203000 Foam Strip Front/Back Each - Long (need 2) (TS2205045) $55.69
DK-203010 Foam Strip Sides Each - Short (need 2) (TS2205046) $53.17
Cheaper foam may compress too much or not enough, and it may deteriorate sooner than expected. Been there, done that.