You know what - check
www.danscomp.com under 'cranks'. Then pick out a couple of the crank arms that have built in spiders. There are some by Dotec that are particularly inexpensive. Then call up Dans by phone and find out if you can custom order a specific length for those cranks. If you currently have a square spindle, then there is a good chance the crank arms you receive will fit that spindle and odds are also good that the current integrated spider is 110mm. If you need a new chainring, that is also available on that site.
If you end up needing a new bottom bracket with a square spindle, once again call up Dans and order it specifically for the crank arms you receive from them. They have several bottom brackets in stock.
FYI: The bottom bracket on your frame is the tube that is at the very bottom of the two triangles that your cranks go through... The hardware that your cranks ride on which is made up of a couple of bearings and some bearing cups is ALSO called a bottom bracket. This can be confusing to people, so I wanted you to know. If you look at
www.danscomp.com you will see photos of crank arms similar to what you already have and you can also look at photos of what makes up a bottom bracket. Most of the bottom brackets sold on Dans also include a spindle which (technically) is actually the third piece of a set of 3-piece cranks.
Most complete sets of 3-piece cranks include 2 crank arms and one spindle. They also, typically, include a bottom bracket. Check before you buy though and maybe do some measuring of the spindle inside the current cranks on the bike.