I have never looked, but I can't imagine anyone makes an IDE SSD drive... So it might be a very moot argument.. However, there are plenty of PCI sata cards out there that you could pop in and plug an SSD into.. You might need to stick with an early generation of SSD as some of the new ones require sata2 or 3 to even work, but that wouldn't be hard to find.
Just to clear something up, the interface bus, like IDE or SATA, does not dictate the speed of the drive. But if the interface is not at least as fast as the drive/controller chip, it WILL limit the performance. Putting a modern SSD on an IDE bus would be like sticking a Lamborghini motor in a Honda.. nothing past the flywheel would be able to take advantage of the power. As faster data busses have come out, it has paved the way for faster drives. SSD has evolved a lot in the last few years, and my "state of the art" SSD from 3 years ago is nearly 3 times slower than the current models. SSD is one of the few technologies that overcame the data bus speed before a faster version was available.
And I am not sure about your comment about reliability.. mechanical hard drives are far more reliable than any flash based memory.. Granted, in an environment where the data will only get read and pretty much never overwritten, it will likely last indefinitely. But typically a hard drive undergoes a LOT of overwriting over time, and flash memory breaks down pretty fast as this happens. Any SSD built for critical use is still only good for about 5 years and has a lot of extra capacity set aside to replace failed cells.
On a side note, I can't help but remember quite a few years ago when the SCSi bus was the fastest interface available, so when I had the chance to change from IDE to SCSi, I jumped on it. I was SO excited to see how much more performance I would get, and the day I got my drive in I quickly slapped it in and cloned everything over and ran tests.. only to find out I gained 0% performance in ANY category.. At the time, hard drives had already reached a limit on performance, so regardless of whether the bus was twice as fast, the source was still just as slow. Over the years as faster busses came out, the drives only made marginal increases in performance.. 10k and 15k rpm were usually the best way to squeeze a little more out, but we were talking 10 or 15% gains for each new drive technology. The first SSD's were barely faster than the fastest IDE drives (ie the raptor).. And then the technology exploded and suddenly the speeds were 3 or 4 times faster and the data bus's limits were being hit.
Anyway, just remember that a computer is only as slow as it's slowest component. Even with a faster drive, if you are maxing your memory, cpu, gpu, or PCI bus, you will see very little if any gain from a faster drive. Usually the slowest part of a computer is the drive though, which is certainly true of older IDE stuff, so you will likely see faster load times, so if that is your goal, go for it.