As @Luke stated, the EX4600 is a fiber switch, which means it additional SFP optics to make any interface workable. The Base unit contains 24 SFP+ ports (accept either 1GE or 10GE optics) and 4 x QSFP 40 GE interfaces. There are also 2 x expansion slots. Expansion modules are either 8 x SFP+ or 4 x QSFP. Any of the QSFP ports, either the 4 on the base or via optional expansion slot, can be channelized and provide 4 x 10GE instead of 1 x 40G. This is done by a combination of configuration and using the proper 40GE Optic which provides for 4 x 10GE channelization.
The EX2200/3300/4200 (all now End of Sale) and the newer generation EX2300/3400/4300 (inlcuding MP versions) switches all have Limited Lifetime Warrenty Support (LLWS) which covers both HW and SW download support. This is included free with any switch purchase. The HW support is next-day ship. What is not covered is any TAC support. TAC support on top of LLWS can be purchased via CORE support; requires min of 10 units of any specific model. Any other service contract such as ND (next-day arrive) or SD (same day arrive) includes TAC as well as specific HW support.
Please note that only switches purchased via an authorized Juniper re-sellers (i.e. non-Gray market) are allowed any level of support. Non-authorized purchased are void of LLWS, or ability to additionally add any level of support.