Also, if there are any Magento users around here, what host are you currently using? What about your website's performance, stability and uptime?
Finally, I have done a search and couldn't find anything suitable so please don't leave a message saying "Use the search" because it's blatantly obvious that you just want to leave a reply so I look at your hosting company.
I took a look at your requirements and have not seen anything outside the realm of what most Web Hosts usually already have compiled on their servers.
One way to find a host would be to check out the shared servers offers then search their names to ensure that there are little to no negative remarks against them along with positive reviews in this forum. Also be sure to look at how long they have been in business because if they are new they may not have any reveiews for or against.
Also, when you have checked and found some that you are interested in, I would still contact that host first before buying and ensure that they will be able to support those requirements just in case.
Blue Bell Web Hosting, LLC
600 W Germantown Pike Suite 400; Plymouth Meeting, PA 19462
Only requirement I can see as an issue would be PDO as I've read several complaints of hosts not having PDO and pdo_mysql loaded. You're probably going to need to inquire at each host about them having it.
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I would recommend checking the offers section here on WHT, find a few companies that are within your budget and meet your requirements. Simply after you have compiled a list of few providers, do some research on each of them for feedback and also test their response timings.
Your budget is good, you shouldn't have any trouble finding a reliable provider, best of luck