Ranger 33 to an Ericson 34?
If I am not mistaken, 1987 was around the year that Pac Seacraft bought out Ericson so I am not sure whether these are Ericsons or PSC''s. They are a nice boat that should offer better fit and finish than the Ranger. Working down your list the deep keel model offers a significant speed advantage over your old Ranger 33. The shallow keel model offers much less of an advantage. The Ranger is getting to an age where the encapulated keel could become an expensive problem. It is not unusual in a boat of this age to find that the encapsulation envelope has separated from the ballast. A proper repair is very expensive. I have never heard anything one way or another about Ericson/PSC''s keelbolts. I don''t know if the Ericson 34 will provide more room. I believe that the original Eriscon built 34''s used a post hung rudder and that PSC added skegs to some of the models that they continued to produce.I don''t know if the 34 was one of them. I do not think that you can add davits capable of holding much weight. These boats have a fairly long overhang and small transom area and so would tend to squat with the weight of davits, a dinghy with an engine hung off of the transom.
They seem to sell for somewhere between the mid $50k to low $60 range which is moderately expensive for a boat from that era.