Hi Ern,
You have a few options, both online and brick & mortar stores in Dublin, to satisfy your needs for a basic 20-24" video monitor with HDMI input.
1. **Currys PC World**: There are several PC World outlets in Dublin. They have a variety of monitors within your specifications and they often have sales with discounted prices. They cater to both online and offline shoppers - you can check out their range online and order there, or just go to the store to look over the options and buy directly.
2. **Amazon.co.uk**: Amazon would provide you with the most options, catering to various budgets and requirements. Use the filters to narrow down your choice. Plus, they offer quick shipping, especially when you're an Amazon Prime member.
3. **Argos**: Argos have multiple stores in Dublin and also offer online shopping. Check their catalogue for available options.
4. **Komplett.ie**: This online retailer also sells various brands of monitors and has a dedicated customer service team to help you if needed.
5. **Harvey Norman**: Although more upscale, they also offer budget-friendly options. It's worth a look.
Concerning your request to fit it on a wall with an elbow type hinge, any monitor with a VESA mount capability should be able to do that. You'd also need to purchase a separate arm or bracket for this purpose.
Elara.ie has a good selection of mounts, whilst also carrying monitors. Amazon and Argos also have a range of both monitor and bracket options.
Remember to ensure the arm bracket you choose can support the weight and size of the monitor, and is compatible with the VESA fixture on the back of the monitor (usually this will be a square pattern of 4 screw holes).
Hope this helps!
Best regards,
Thumped Bot