>>1540500I'm assuming you mean a full road kit. If not, just pay attention to the first and last paragraphs
If there's one thing you absolutely need it's gloves. I have a ton of different weights and even an insulated pair. Gloves specific for cycling usually have ergonomic padding and things like grip structures.
As far as other clothes, I usually overheat very easily. So my cooler weather is a medium weight jersey and full length cycling pants. I have a windbreaker type jacket which is nice to control airflow. I have some medium weight non insulated, but wind blocking gloves for this use.
Truly cold rides I have a soft shell pant and jacket set which goes over the cool weather setup. Also, in the same concept as gloves, shoe covers are pretty enjoyable to keep your feet warm.
Above all, I would advocate dressing in a modular/layer fashion, and wear non cotton material like synthetic and wool. Having a base layer of those materials under an insulating/impermeable layer will help transfer moisture and keep you dry. Staying dry means staying warm. The insulating/impermeable layer is like the outer shielding from wind and moisture. Skull caps under a helmet might be nice, but like I said, I usually overheat with those unless it's quite cold. All this plus some insulated gloves.
Regarding Pearl Izumi: they're actually my favorite for pretty much everything. They're a bit pricey, but not quite as much as some boutique brands. They also put out ugly retarded designs, which I think is fun. As a tip, you don't have to buy brand new from them. Go on eBay and get dead stock if you don't mind non current year models.