Congrats on the a6400! Its a killer little camera for travel and youll love how compact it is for walking around Italy. Dont stress too much about the 150 quid limit, you can totally get what you need without breaking the bank if you shop smart. For the batteries, honestly I have been super satisfied using the SmallRig NP-FW50 Camera Battery and Charger Kit. I know people worry about third-party stuff, but SmallRig is a solid brand and their dual charger is way more convenient than charging inside the camera body. I usually get through a whole day of heavy shooting in cities like Rome with just two of these and the original Sony NP-FW50 Rechargeable Battery Pack as a backup. I have never had any issues with swelling or frying anything... basically just dont buy the absolute cheapest no-name ones and youll be fine. Regarding the other bits:

• Definitely go with the Ulanzi MT-11 Flexible Tripod over the GorillaPod. I have owned both and the Joby legs definitely get limp after a few months of heavy use. The Ulanzi feels much more robust and that built-in cold shoe is actually a lifesaver for accessories.
• Grab a ULBTER a6400 Screen Protector Tempered Glass. Sony screen coatings are notoriously soft and scratch way too easily.
• Maybe snag one more SanDisk 128GB Extreme Pro SDXC UHS-I Card. Your 64gb will fill up faster than you think if you are doing 4K video or shooting RAW. Italy is gonna be amazing. Just keep your gear light and focus on the pasta and the views!

Like someone mentioned, you gotta watch the coins! Honestly though? Skip the tripod for Italy. Youll hate lugging it through crowds. Grab a Peak Design Cuff Camera Wrist Strap for security and a K&F Concept 49mm Variable ND Filter for that harsh Mediterranean sun. Its way more practical than a GorillaPod for street shots and keeps you light. Definitely a better use of your 150 quid!

Regarding what #1 said about "Congrats on the a6400! Its a killer little..." - i totally agree. i have run tens of thousands of frames thru these sensors and they are solid. but technically speaking, that 64GB card is a bottleneck. if you are shooting 100Mbps 4K video in Italy, you are looking at barely an hour of footage before you are stuck deleting stuff on the fly. I have tried many brands over the years and i usually suggest a V30 or V60 card for consistency. check out:

• Lexar Professional 1066x 128GB SDXC UHS-I Card
• Kingston Canvas Go Plus 128GB SDXC V30 Also, the ergonomics on the a6400 are kinda cramped. the flip-up screen is basically useless if you put a mic in the shoe. i would grab a SmallRig Cold Shoe Relocation Plate BUC2334 to move the mic to the side. and since you will be in the sun, a K&F Concept 40.5mm Variable ND Filter ND2-ND400 is huge for keeping your shutter speeds right for video. the extra grip from a SmallRig L-Bracket for Sony A6400 2331 makes it way more comfortable for long days walking Rome too... trust me on the grip.

Did this last week, worked perfectly