Hi Julius,
Welcome to the forum. I can't recommend one over the other as far as Bob Shore's or Jerry's V4, but since this would be your first, don't rule out a single cylinder or even a twin as a first effort. That is in no way a statement as to your skills as a machinist, which no doubt exceed mine. Only that the transition from commercial machining to small engines may not be seamless and it may be good to start with something less complicated to get that first success under your belt. I have no doubt that your skills are up to the challenge, its more that things aren't always what they seem at first glance. There are numerous posts on sterling and atmospheric engines for example here on this forum, and many of them relate to the finiky (sp?) nature of getting them to run well, however simple the design may look on paper.
Whatever your decision, best wishes...and again welcome to HMEM.
Bill
