Whether you're looking to get a little extra length or looking to secure your home electronics, choosing the right type of extension cord with surge protector is important. 
Some light-duty extension cords are good for plugging in simple electronics and charging cell phones. For more pricey items like televisions, sound equipment, computers and laptops, you'll want to use a surge protector with a warranty and can protect your equipment from power surges.
So How to Choose Extension Cords? and How to Choose Surge Protection?

► Powerfix extension lead with surge protection
- Protects electrical devices from surges up to 3,000V
- With on/off switch light and child safety feature
- Powerfix extension lead surge protection £7.99
- Protects electrical devices from surges up to 3,000V
- With 6 sockets, on-off switch light and child safety feature
- Cable length approx (m): 3
- 3 year manufacturer's warranty
► Outdoor extension cord with surge protector
Tripp Lite 7 Outlet Surge Protector Power Strip, Extra Long Cord 25 ft., 1080 Joules, Lifetime Limited Warranty & $25K INSURANCE (TLP725)
Style: 25ft Cord, Price:    $28.80
• PROTECT ANY ELECTRONIC DEVICE FROM POWER SURGES & SPIKES: Surge Protector with seven outlets protects your PC, personal computer, laptop, printer, scanner, router, phone, fax, modem, television, lamp or any other home/office electronics from dangerous power surges, spikes & line noise
• SAFETY FIRST! HIGH JOULE-RATING - CONFORMS TO UL 1449 SAFETY STANDARDS: Automatic shutoff cuts power to all outlets when the protection circuit has been compromised. Diagnostic LED confirms your connected equipment is protected. 1080 joules mean maximum protection for your equipment. Conforms to current UL 1449 3rd Edition safety standards
• LIFETIME WARRANTY, $25,000 INSURANCE: Lifetime Limited Warranty and $25,000 Ultimate Lifetime Insurance covers any connected equipment damaged by a power surge
► Best extension cord for surge protector.
1. APC P11VT3 11-Outlet Surge Protector

APC 11-Outlet Surge Protector 3020 Joules with Telephone, DSL and Coaxial Protection, SurgeArrest Performance (P11VT3)
2. AmazonBasics 6-Outlet Surge Protector

AmazonBasics 6-Outlet Surge Protector Power Strip, 6-Foot Long Cord, 790 Joule - White
3. Belkin BE108000-08-CM 8-Outlet Surge Protector

The Belkin BE108000-08-CM 8-Outlet Surge Protector provides maximum protection of all your sensitive electronic devices with a 2500-joule energy rating.
4. HOLSEM 12-Outlet Surge Protector

The HOLSEM 12-Outlet Surge Protector fetures 3 USB ports with 6 compactly allocated sockets and 6 widely spaced sockets.
5. Belkin BP112230-08 12-Outlet Surge Protector

The Belkin BP112230-08 12-Outlet Surge Protector provides powerful protection for your workstations, printers, broadband modems, home theater systems and everyday household electronics.
6. BESTEK 8-Outlet Surge Protector

The BESTEK 8-Outlet Surge Protector features four built-in USB ports enhanced with fast-charging technologies supply a charge of up to 5.2 amps.
7. APC P11U2 11-Outlet Surge Protector

The APC P11U2 11-Outlet Surge Protector offers protection for up to 11 electronics, in addition to conveniently charging your mobile devices via two additional USB ports.
8. ON Smart Solution 4-Outlet with 4 USB Surge Protector

The ON Smart Solution 4-Outlet Surge Protector offers the flexibility to charge while protecting multiple devices.