Property Tax payment

You can have any lawyer handle it for you each year.  You can just send him/her the money via Western Union each year.  Also provide a letter (in Spanish) giving the lawyer the authority to make payments for you.  The lawyer should also have a copy of your passport.  If you are just a few months late paying your taxes each year (the interest is peanuts), so do not worry if you are four months late getting down here.  You could set this same arrangement up with your neighbour down here, and provide the same permission letter etc.

You don't need a permission letter. Also, some property taxes can be paid online, BN Internet Banking.

We have three owners in our deeds and they would not accept the tax payment unless we had authorization from all three owners, so now we take a letter from the third party (in Spanish) and they accept the money.  Costa Rica is very "Willy Nilly" as those who live here know.  If you go to a bank each teller will tell you something different, nothing is consistant down here.  On the other hand we were able to pay our water bill a year in advance without the permission of all three owners.  Nothing is normal in Costa Rica when it comes to dealing with government.

The short answer is no, I don't know anyone or company that does that. But here's some further info:

I have had friends pay taxes in San Ramon without a letter or anything. I suppose it depends on the Municipality where your property is.

I'm sure your attorney could pay it for you; the price might be an extra $25-50 or more for their trouble.
If you have a bank account you may be able to pay it online.

When you pay it, see if you can pay a year in advance. I paid in advance, I don't remember if it was a year or less than that. There was a maximum or I'd have paid it 3 years or more in advance!

Yes you have always been able to let it go for months with no penalty. However they are getting more and more bureaucratic and when I let mine go for a year (out of ignorance), I was told that they were moving towards taking the property away or something severe like that. So just in case rules change, I'd advise paying it asap, and paying in advance, and putting at least a couple Reminders into your email, or other calendar reminder systems you may have access to.