Info and pic posting

I am developing a website that sells web space (advertising space) to persons selling realestate. How it works is someone who is selling property will purchase space for $xx.xx online via the secure area of the website.

Once the transaction is complete they will recieve and e-mail with a randomly generated password which will be used to enter another area of the site where the person can post the photo(s) of their property, add descriptions, pricing contact information etc. This information along with the photos are posted on the site for a period of time (depending on the package they purchase). This will be (obviously) fully automated. After (lets say...one month) the photos and information would be automatically deleted unless the client purchases more advertising time.

My question is....

Would it be easier/better to have custom scripts written to do all this or to find some automation software that would do it for me. If custom scripts are prefered where can I get additional information on doing this properly?

If the software avenue is the better choice are there any suggestions for which software to use and where can I get it?

BTW I am an experienced web designer who was self taught and have used premade CGI, Perl, and java scripts in the past and know pretty well how they work and why they do what they do but I would be lost pretty quicky if I were to try to develop this script on my own.

Thank You in advance