American Apparel.

Op here. Thanks for the suggestions. Even though thesis my second I seem to be experiencing some amnesia (it has been 5.5 years!)
Do you swaddle baby when you take then outside as well? I have a k'tan carrier I was going to use the first couple months. My last child I barely left the house plus it was the heat of summer. This child will have to come with Me to drop older dd off at school since DH only has a week off. The walk is about twenty minutes. I want to make sure he or she will be dressed ok for the cold weather when wearing her in the k'tan. Suggestions are welcome. Thanks again.

Costco, Target (like the circo brand in the packages), Walmart, TJ Max, Marshalls, Ross.

Do NOT use the JJ Cole Bundle Me in a car seat. They are not safe as they alter the car seat. Use a warm blanket instead. You can use them in a stroller.

Carters has gender neutral sleep n'plays and onesies. You can also get gender neutral buntings which can act as a winter jacket (just not while in the carseat).

You can also use a JJ Cole Bundle Me instead of the bunting, which may be easier.

Unique thrift store

If you want really cheap, Walmart and Kmart have multi-packs of zippered sleeper type outfits for infants. They have the typical color schemes--pink, blue, green. I got a couple of the green for my b/g twins when they were born because I wanted easy clothes (not over the head) that zipped and could be put on either. I think mine were from Kmart and were Gerber.

Yeah, Carter's, yellow, green, and white. Some browns. Usually a good selection at Kohls, decent at Target. BuyBuyBaby has a lot but they are a bit more expensive. Amazon.com

We got a bunch from Buy Buy Baby. Also Old Navy and Carter's.

Try TJ Maxx, Marshalls, Nordstrom Rack, Children's Place, Old Navy

I had a January baby, and found several packs of neutral footed sleepers at Target (Gerber brand, maybe?). Also got some long-sleeved plain onesies and kimono shirts. Outfits and such didn't really matter those first few weeks because he was never really unwrapped from the swaddle. Gerber is plain and not terribly thick or soft, but as a layer under the blankets they got the job done, without feeling like we'd spent a lot of money on stuff he wouldn't wear for long. Gifts from family filled in the rest.

By the time we were really out and about much, we had plenty of other outfits.

Old Navy has the best onesies (IMO) which you can get in a 3-pack online. They do come in a long-sleeve version and they are much softer and thicker than any of the others I tried. They also have some gender neutral pants (beige, brown, white) in cotton and fleece and usually some printed onesies or romper type outfits that would work for either gender.

I hate to say it, but there aren't many gender neutral options. I had DS last March and gender was a surprise. I struggled to find things ahead of time that were truly neutral and also cute. I couldn't wait to go out and buy some boy things once he was here, as the gender neutral stuff wasn't cutting it. Depending on when in Jan you are due, you could probably pick up some stuff online for cheap (on sale) once DC is here.

I went to a carter's outlet b/f my first was born. You had to hunt a bit, but I was able to find solid, bright colored options. It gets harder as they get older, but unisex infant sized clothing does exist. Old Navy is pretty good too. You may also want to try H&M.

Layer.

That are preferably warm as well? My baby (don't know the gender) is due in January and I would like to fill his/her dresser with some warm clothes that I can thrown on him or her while dropping older dd to school. I see tons of short sleeve onesies that are neutral but I think something warmer is needed!