Webserver: Sata Raid 1, 5 or 10 or SAS Raid 1
 

I'm upgrading to a new web server. The primary purpose is a vbulletin message board site.

In terms of the budget, I have four options:

Raid 1 - 2 x 500 GB Sata 3.0
Raid 5 - 3 x 500 GB Sata 3.0
Raid 10 - 4 x 250 GB Sata 3.0 (I could upgrade to 4 x 500, but don't need the space and by going with the 250 GB drives, the price is similar to the other Sata options)

Raid 1 - 2 x 180 GB 10k SAS

In all cases, the amount of drive space is way more than needed, so this is just about performance. The SAS option costs the most, with the three Sata options being similar in price.

I'm leaning towards the Raid 10 Sata option. Any thoughts?

Raid 5 should be a little cheaper and it gives you both speed and redundancy. That's what we use.

I would recommend you to go with the SAS drives, especially since you running a forum.

RAID10 seems to be the choice for any sort of database server these days. While I realize your just running vbulletin, alot of it's speed and realiability is going to be a hybrid of how well the backend database runs mixed with the configuration of Apache or Nginx.
Most online articles I've read/seen have pushed databases for RAID10 and nothing else.