Mountain Biking - Replacing my nasty Judy TT with a new fork; + upgrades to bike

Soooooooo I'm fairly new to mountain biking, only having had my Trek 4500 since September. In short, the Judy TT is a POS and I want a new fork:)

I've spent a considerable amount of time (hours online) today and last night, searching this forum, reading reviews, etc. etc. on different forks and other accessories. I decided on the 2005 Marzocchi Mx Comp ETA Fork 120mm (http://www.blueskycycling.com/view_product.php?pid=706_39) at the outstanding price of $199. I do a lot of XC stuff, along with commuting...nothing super hardcore. I think it'll be perfect.

My question is, is fork replacement something I should do myself? I'm not experienced in messing with bikes, however, I'm definately not mechanically unskilled. I read these instructions (http://www.ehow.com/how_14185_install-new-bike.html)...cutting the pipe?? My goodness. And I don't have a crown tool or whatever it's called. Is this something I should pay my LBS to do? About how much would that cost? I did buy the bike from there, after all.

Another question: What do you think of these pedals (http://www.jensonusa.com/store/product/PE707A09-Shimano+Pd-M424+Pedals.aspx)? I spent quite a bit of time looking at pedals...I want some where it would still be possible to use them with normal shoes. Again, should a shop install these?

Thanks!

You can do the fork, but do a search here for a bit more detail. PVC pipe will work to install the crown race. Cutting the steerer is easy, but you need to measure at least 6 times, and allow yourself a bit of stack height for future changes.

Those pedals are easy to install with a pedal wrench, and work with or without the correct shoes. Much better to get some soft-soled SPD compatible shoes.

A tube cutting guide (http://www.performancebike.com/shop/sub_cat.cfm?subcategory_id=4209) would be a worthwhile investment for cutting the steer tube and keeping the cut square. Like Expatriate said, measure multiple times before you cut and give yourself a little slack. If you cut long, you can recut it or add a spacer. If you cut short, you have to work with what you have left.

Having your shop cut the steerer isn't a big deal. Be good to them, and they won't charge much. Less than $20 in most cases, which should include touching up with a file. They may even swap the races for you.