Yesterday I ordered my open sights. I got MagPul Back-up Sights (MBUS), front and rear sights from machineguntours.com for $85 shipped - about $15 cheaper than any other site I found.
I received the Prince50 Bullet Button and Action Wrench a couple of weeks ago, talk about good quality - I am impressed. The magazine that also came is really nice. I can't wait to get going on this build and get the kit in the mail from Del-Ton.