Really is down to personal choice and also what you have on the front end of your Nav, be it a Nudge Bar, Bull Bar or nothing at all. This will determine what you can fit and where. Just to note that all lights on a vehicle (in WA at least) must be in pairs. I have seen a number of 4x4s with 3 spotties in front of the grill and it would take a pretty pedantic cop to pull you over but it is still illegal.
I spent some weeks researching spotties and decided on the Lightforce 240 XGTs. They really do make a difference and I would buy them again.
Like everything though they have their pros and cons such as cost, they are a target for the scum of the earth (thieves) and to get the spread effect you have to buy filter lens for them that are also easy to walk off with. They do however turn night into day.
Most people will recommend HIDs no matter what the brand. I will concur but again, this will add to the cost. For example, my XGTs cost me $550 for the pair (non HID) but will set you back $700 each if they are HIDs.