If the rewards are NOT limited rewards -
Add them all up for the pledge amount and choose one. When I send the surveys out at the end of the campaign you can specify which rewards your pledge is covering.
For example: If you want a 5 x 7 watercolor and 9 x 12 mixed media sketch
$85 + $95 = $180
1) Put $180 into the "pledge amount" box
2) choose either of those two rewards below the pledge amount.
If one of the rewards IS a LIMITED REWARD -
For example: You want the Early Bird 8 x 10 watercolor and an 11 x 14 watercolor
$125 + $270 = $395
1) Type $395 in the "pledge amount"
2) choose the LIMITED REWARD, 8 x 10 Early Bird Special below the pledge amount
Again, once the survey is sent out, you can specify
Because of the way Kickstarter is set up, you can not choose 2 limited rewards.