First Grand Complication Advice

[Texas Our Texas]

I’m looking for some wisdom from the assembled brain trust here on the forum. Though I haven't posted, I read a ton, and this has been an incredibly helpful community as I continue to learn and become a more informed collector. 

I had a nice business milestone occur, and I plan to mark the occasion with an exceptional timepiece. Right now, from the current line, the two primary pieces I am considering are the 5270P (green dial) and the 5370P, with the 5204G as an outside contender. This would be my first grand complication, and I would get the piece from my AD. From retired references, I also love the 5204R with the grey dial and strap.  I would also probably let my AD source this for me, as he has done so (and offered to do so) with other retired references.

My budget is approximately $300K or so. I buy a piece or so a year but not at this price point. I expect it will be 3-5 years before I am shopping at this level again. 

So my question is: which piece would you recommend and why? Are there pieces I’m not considering that I should? I’m not married to buying a current release Patek, so if there are other vintage pieces that I should think about, I’m entirely open to that. 

Aside from just enjoying the piece, I do care about the long term vision on collecting, including value of the piece, best way to build a collection, and building the relationship with the AD for special or application pieces down the road.  Not sure if it would affect anyone’s thoughts, but if I end up underspending the budget on the main piece, I’ll likely buy a 5172G (blue dial), a world time, or maybe a 5170P. All are on the roadmap for eventual purchase, but I’d use this as an excuse to do it at the same time. 

Thank you all in advance for the thoughts.