If you want 300m or more the only choice for a new from store model will be the Submariner (300m) or the DeepSea (3,900m). All others will be 100m or less. If you want to expand your options to preowned, then the SeaDweller (1,200m) is another option. As someone who's owned all three models, the SeaDweller would be the one I'd go for. The Submariner would be 2nd and the DeepSea 3rd. I love the size & look of the DeepSea, but absolutely hated the domed crystal and the fact the bracelet is 22mm at the lugs and then tapers down to a measly 18mm at the clasp..
As to 'deals', new from an AD? Very few & far between, especially on these models. Maybe 10-15% off list (maybe, not guaranteed anymore) unless you've got a stellar relationship with an AD. If you're willing to look at preowned, then deals can be found. BUT, you need to do your homework, know what you're looking for and at and be able to separate wheat from chaff as there's lots of bad deals (as well as scams) out there. But with some due diligence and common sense (ex. if it looks too good of a deal it probably is) you can get fair deals on preowned models.