I agree, Ilfosol-S would be a good substitute for XTOL. Another good alternative would be Edwal FG7. If you choose FG7, you probably will want to add sodium sulfite to lessen the grain with HP5+. I used this combination a lot before going to PMK, and it's as good or better than any of the commercial developers.(posted 8369 days ago)PMK is certainly an alternative you should consider. Few developers match the quality you can achieve with PMK. If you choose to mix your own from a kit, be very careful not to inhale pyrogallol dust! You can buy it pre-mixed in liquid form from Photographer's Formulary.
One last point, FG7 and PMK have excellent keeping properties. PMK will last years with reasonable care.