so I will need your suggestions for best way to store it for long term - cold storage preferred for investment
Other member already provide good link/suggestion. But what are your criteria to determine best way to store Bitcoin long term? Durability? Easy to use?
and also some way I can spend it without using banks while I travel abroad.
The common approach is using mobile wallet. But you shouldn't store too much Bitcoin on it, since there's higher risk your mobile device could get stolen or hacked. If you want to use Bitcoin on place which doesn't accept Bitcoin, you either need to sell it as needed or use Bitcoin debit card which convert deposited Bitcoin into fiat.