Bassinets and Mattresses Rec (travel and home) [on]

Hi everyone! Expecting FTM here (due mid April with baby boy). Two questions here! 1) We were given a bassinet/cradle from my in laws to use for the first bit before transitioning him to his crib after a few months. Due to it being my husband’s when he was a baby, the bassinet is not a standard size we can find today, it is 18x35 inches and I am having trouble finding a mattress for it. Was wondering if anyone has any recommendations? Is there companies that do custom sizes that won’t break the bank? Whenever I google it crib mattresses show up which are bigger and thicker so will not work. From my understanding bassinet mattresses should be thinner and firmer/more like foam toppers of some sort?

2) Any recommendations for travel bassinets? For when we go to grandparents etc., someplace safe we can set him down during family dinners or in between feeds etc? That can then be packed up and put in the car easily? I am getting a pack and play for the future but figured that was too big/bulky to carry around when he will be at his smallest, especially since my husbands family is quite large and space will be limited during these visits. I found one off of Amazon and then got freaked out over a horrible review.

Open to any suggestions, still very much new/overwhelmed with all of this so any advice is appreciated!! Thank you in advance!

Edit: thank you guys! You convinced me (along with some more googling) that we should be looking into a new bassinet/possibly used FB marketplace one. If anyone has any suggestions they swear by as to brand would love to hear it!