The S1100 can’t stretch in real time like the Octatrack, but yes, you could in theory timestretch the samples you want to the length needed, then trigger playback from the Octatrack. It doesn’t have any BPM stretch function by the way, it’s done by percentage, so getting exact tempos out will require some maths.
I don’t know what OT TS forum is, but when you say ‘superior’ I would point out that that is highly subjective, and in the case of complete tracks or parts then more likely than not it’s not going to be what you expect. Perhaps check out some audio demos on Youtube etc. And if you do decide to go the classic sampler route, as @obscurerobot says, get ready to do some home chores while waiting for the stretch to compute.
I like the operation of old samplers, lots of buttons and screens to page through. It’s a more considered approach because you have to really plan out what you want to do to the samples with far less visual information to guide you, which gets you in a different head space. Very slow way of working. But don’t believe everything you read about the ‘sound’, especially not of the later Akais. S1100 was considered a very hi-fi machine in its day. By the time of S5000/6000 they were basically rack mount computers designed for CD quality audio playback, very little ‘mojo’.