I would go with 4 multi gene females first:
- Lemon Blast
- Pastave
- Bumblebee
- Pewter
These would run about $500 a piece. Then in a year or so I would go ahead and purchase a male super pastel. He would roughly run $350-$400 (they are slowly coming down in price). This would give you a pretty nice starter group with no normal offspring in any of the pairings. Just make sure you get the best example of each morph.