Your plants look good and should be flowered very soon. If you plan on flowering in a week or so I wouldn't clip anything, but I would give it a fair dose of nitrogen rich nutrients just before you trigger them to bud. They seem a little light although it is hard to tell with an HPS because of it's colour. If you don't give nitrogen since you have not given any yet and trigger you will probably have premature yellowing of your leaves which will ultimately stunt bud growth. One good dose of high nitrogen veg and then switch to bud the rest of the way (make sure it has micronutrients). You should get a nice yeild off those babies. Great work for a first grow! Your a born grower.
TGT