Shuo,
First off Hello and Welcome to Tradgang.
are You looking at any type of bow? The Horse bows or those used by the huns (Turkish) are great bows. as said, ELB are very long as are those made in Japan of old. A small frame bow can be moved around way easier then longer bows as we all know, but both have their good and bad points.
Longer bows are more forgiving, No finger pinching, more working limbs.
Shorter bows are Great for those tight spots, From Treestands and pop-up ground blinds and also box blinds.
The best thing I would say is. If You could try each of those types of bows first to see what You like and shoot better would be a best way to find a bow. As for not having a shelf, You could add a floppy rest (small piece of leather glued to riser to make a location/rest for the arrow.
They will help as a locator so You always have the arrow sitting in the same spot and help with clearance (So the quill doesn't run into Your finger)