Aircraft and base is all seniority based. You get what you can hold. 175 tends to go senior, esp DFW. 145 gets the rest, split by DFW, LGA, ORD, MIA. MIA and DFW are more senior and rarely come up for bid.
How quickly you get to 1000 depends again on equip and base. 175 FO’s have easily been ready in less than 2 years. 145 guys are over 2 years on average. And yes, lots of guys leverage reserve to adjust their arrival at 950 hrs if they can.