Any recommendations for professional install help for newbie?

I would be surprised if I could afford to pay what it would cost, but failing to ask first would be just plain stupid I guess. I’ve read through a lot of stuff on the subject and have come to the conclusion I just cannot do it myself without screwing up my blog – obviously, I’m not very technical.

Here are the relevant facts:

I built a blog on my own domain, FTP’ing from Blogger to my own server for creating posts. I now have a little over 300 posts with unique URLs, plus Haloscan for commenting. I want to switch to WordPress, if possible, but could only do it if:

A) All of the haloscan comments are preserved –
B) All of the original post URL’s are preserved –
C) Minimum downtime, preferrably none –
D) I need to have the ability to add and remove guest posters with ease –

I now have too many links coming in to many of my individual posts as well as my main page to risk losing those and the decent blog ranking I’m starting to aquire, which is why I need all the unique URL’s to remain in place.

Last note; I’m somewhat familiar with WordPress from the user end since a group blog I post to uses it, which is why I prefer it vastly to Blogger.

Any suggestions / comments are appreciated. Thanks.