How do I accomplish integrated online payment via Chase Orbital (Paymentech) for a PHP website?

I have a client that is a non-profit childrens' shelter, their website is a custom handcoded simple PHP/mysql brochureware site, this is their current page for ONLINE DONATIONS set up to use paypal:

http://www.jpkids.org/index.php?n=4&s=20

We've staged how we'd like to do integrated online donations through Chase Orbital (Paymentech), who they bank with and already do non-web donation transactions with:

http://www.jpkids.org/index.php?n=4&s=20&test
(click make a one-time donation)

I've done integrated payment using Trust Commerce's tclink.php, which made it pretty easy.  Get an SSL certificate, gather up the card number, name, expdate, CVS, send it off, get a code back.  NOT A HUGE DEAL - I guess because Trust Commerce was nice enough and php-friendly enough to provide the tclink.php API (if "API" is what that's called, forgive my ignorance here - I'm not a heavy-duty programmer).

The Chase Orbital route however so far looks worse than revising Tax Code.  There is no PHP API, which is sort of shocking to me, and as I google and search for code examples or others in the same situation, all I find are expired project bids on rent-a-coder.com and getafreelancer.com.

I understand (I think) that I would use PHP to output XML (which I've done to create google sitemaps), and then access the XML gateway URL using https protocol, with a non-authenticated SSL session, Chase has my IP registered.  I have no idea how to do this last part though.  Also, there are like 50 pages of XML elements defined in the "Orbital Gateway Interface Specification 4.3.pdf" doc (attached).  No code examples... I feel like they don't want normal people to interface with them, like you have to be a professional programmer or subcontracted by them or something.

I suppose if this should be do-able and it's not as hard as it looks, I'd love to hear it.  But I think I'm also just looking for some bigger picture business-advice:

We're talking about a non-profit who wants to accept donations through their website.  Should they really be expected to pay thousands of dollars to outsource a PHP API for Chase's Orbital gateway??  If Chase is so huge, shouldn't they have the resources to provide this themselves?  Am I missing something here?  Is there an easier route?  Should I just bid to find a programmer for my project, but am I basically asking for a PHP API for Orbital?  Why has no one already done this, or is it out there and I'm not finding it?  Why doesn't Chase provide this from the beginning?  Are they un-friendly to PHP, or just generally unfriendly?  I just keep thinking I can NOT possibly be the first person who needs this, and no-need to reinvent the wheel...

I'd really appreciate some insight and advice from anyone who's familiar with my predicament.  

Thanks so much in advance for your time,
Alan
Orbital-Gateway-Interface-Specif.pdf