Doug, You'll have no problem anchoring for a week. Just make sure the hulls don't leak. Anchor using enough scope. I use a bridle attached to the bridle tangs. I think the 21SC bridle tangs have a extra set of holes that you could put shackles in and then use those to tie the anchor bridle to. If not replace the clevis pins at the bridle tangs with shackles that have the same pin dia. as the clevis pins. Look at the triangle the wire bridles make. Make the anchoring bridle a little a little larger.

You can do a search. This topic was talked about a while back.

Have Fun
Mike